1. Field of the Invention
The present invention relates to a lens barrel and an image pickup apparatus.
2. Description of the Related Art
Japanese Patent Laid-Open No. (“JP”) 7-13059 proposes a driving method configured to drive a lens barrel with a small structure by providing a gear to a cam ring. JP 2004-233925 proposes a technology configured to increase a driving amount of a focus lens without influencing a driving unit in the lens barrel.
However, JP 7-13059 is silent about a reduction of a length of a third cylinder unit in the optical axis direction, which includes a drive ring and a lens holder configured to hold a third lens from an object side. In addition, in JP 2004-233925, a third cylinder unit that includes a three-group lens frame is long in the optical axis direction. Therefore, there has been a demand of a further miniaturization of the lens barrel.